What do consumers believe about future gasoline prices?

A full understanding of how gasoline prices affect consumer behavior frequently requires information on how consumers forecast future gasoline prices. We provide the first evidence on the nature of these forecasts by analyzing two decades of data on gasoline price expectations from the Michigan Survey of Consumers. We find that average consumer beliefs are typically indistinguishable from a no-change forecast, justifying an assumption commonly made in the literature on consumer valuation of energy efficiency. We also provide evidence on circumstances in which consumer forecasts are likely to deviate from no-change and on significant cross-consumer forecast heterogeneity.     

A novel application of Approximate Bayesian Computation for detecting male reproductive advantages due to mating order

Studies of the effects of mating order on fertilization success, classically analyzed as the proportional paternity of the second male, have advanced our understanding of the relative influences of postcopulatory male–male competition and female choice on sexual selection. However, results from these studies are often difficult to analyze because (1) distributions of offspring per dam rarely follow a normal distribution and (2) proportional paternities are never normally distributed. Previous studies partially account for these limitations by using nonparametric statistics. However, behavioral studies are often plagued by relatively small sample sizes and require a more powerful analytical approach. Here, we develop a new analytical framework for studying fertilization bias. Our Approximate Bayesian Computational (ABC) model overcomes many of the limitations of currently employed methods. We apply our model to analyze the effects of male mating order on paternity success in the brown anole lizard, Anolis sagrei. Using our ABC simulation, we find a marked first-male advantage: first males sired approximately 80 % of the offspring in our study. Next, based on re-analysis of four previously published datasets, we show that traditional statistical methods often over- or underestimate biases related to mating order. Moreover, by comparing our model to more traditional statistical tests, we show that the ABC method is robust to relatively small samples sizes and should therefore be useful for studying mating-order effects in a variety of systems. Our model is implemented as an R package, ABCp2, and is freely available for use.     

GPS and time-depth loggers reveal underwater foraging plasticity in a flying diver,the Cape Cormorant

Knowledge on how divers exploit the water column vertically in relation to water depth is crucial to our understanding of their ecology and to their subsequent conservation. However, information is still lacking for the smaller-bodied species, due mostly to size constraints of data-loggers. Here, we report the diving behaviour of a flying diving seabird, the Cape Cormorant Phalacrocorax capensis, weighing 1.0–1.4 kg. Results were obtained by simultaneously deploying small, high resolution and high sampling frequency GPS and time-depth loggers on birds breeding on islands off Western South Africa (34°S, 18°E) in 2008. In all, dive category was assigned to all dives performed by 29 birds. Pelagic dives occurred almost as frequently as benthic dives. Pelagic dives were shallow (mean: 5 m) and took place over seafloors 5–100 m deep. Benthic dives were deeper, occurring on seafloors mainly 10–30 m deep. Dive shape was linked to dive category in only 60% of dives, while the descent rate, ascent rate and bottom duration/dive duration ratio of a dive best explained its dive category. This shows that only the concomitant use of tracking and depth tags can adequately classify diving strategies in a diver like the Cape Cormorant. Diet was mainly Cape Anchovy Engraulis encrasicolis, suggesting that birds probably displayed two contrasted strategies for capturing the same prey. Flexible foraging techniques represent an important key to survival inside the highly productive but heterogeneous Benguela upwelling ecosystem.     

Choosing ecosystem service investments that are robust to uncertainty across multiple parameters

Info-gap decision theory facilitates decision making for problems in which uncertainty is large and probability distributions of uncertain variables are unknown. The info-gap framework allows the decision maker to maximize robustness to failure in the presence of uncertainty, where uncertainty is in the parameters of the model and failure is defined as the model output falling below some minimally acceptable performance threshold. Info-gap theory has found particular application to problems in conservation biology and ecological economics. In this study, we applied info-gap theory to an ecosystem services tradeoff case study in which a decision maker aiming to maximize ecosystem service investment returns must choose between two alternative land uses: native vegetation conservation or the establishment of an exotic timber plantation. The uncertain variables are the carbon price and the water price. With a "no-information" uncertainty model that assumes equal relative uncertainty across both variables, info-gap theory identifies a minimally acceptable reward threshold above which conservation is preferred, but below which plantation establishment is preferred. However, with an uncertainty model that allows the carbon price to be substantially more uncertain than the water price, conservation of native vegetation becomes an economically more robust investment option than establishing alien pine plantations. We explored the sensitivity of the results to the use of alternative uncertainty models, including asymmetric uncertainty in individual variables. We emphasize the general finding that the results of info-gap analyses can be sensitive to the choice of uncertainty model and that, therefore, future applications to ecological problems should be careful to incorporate all available qualitative and quantitative information relating to uncertainties or should at least justify the no-information uncertainty model.     

Sexual orientation harassment in the workplace: When do observers intervene?

Little is known about when and why observers of harassment incidents choose to intervene. On the basis of a model of observer intervention by Bowes‐Sperry and O'Leary‐Kelly (2005), we examined situational (directness of harassment, relationship to target, knowledge of target orientation, recurrence beliefs) variables as potential predictors of observer decisions to intervene when witnessing sexual orientation harassment. We also examined how costs and benefits analysis and recurrence beliefs relate to the level and immediacy of involvement. Relationship to the target, directness of the harassment, recurrence beliefs, knowledge of target orientation, and costs evidenced some connections to the nature of intervention. We discussed implications for organizations. Copyright © 2011 John Wiley & Sons, Ltd.     

Experimental analysis of 31 risk estimation tools applied to safety of machinery

This article studies differences in the results of using different risk estimation tools in the same hazardous situations involving dangerous machinery. We investigated how (a) types of risk estimation parameters and methods of constructing tools, (b) the number of levels of each parameter, and (c) the number of risk levels influence the results. Consequently, 31 risk estimation tools were compared by using them to estimate risk levels associated with 20 hazardous situations. Risk estimation appears to be tool-dependent, as different tools give different results with identical hazardous situations. The scope of the tool, its use, and construction could explain these differences. This article also proposes a series of rules for constructing tools to alleviate many problems associated with the variability of risk estimations.     

Applying models of employee identity management across cultures: Christianity in the USA and South Korea

Identity management refers to the decisions individuals make about how they present their social identities to others. We examined cross‐cultural differences in distancing and affirming identity management strategies of Christian‐identified employees utilizing samples from the USA and South Korea. Religious centrality, risks of disclosure, pressure to assimilate to organizational norms, and nation were key antecedents of chosen identity management strategies. Risks of disclosure and pressure to assimilate related to more distancing and less affirming strategies when religious centrality was low, but nation served as a boundary condition for the moderating effects of religious centrality. Distancing strategies related to negative outcomes regardless of religious centrality, but affirming strategies only related to positive outcomes when religious centrality was low. We discuss how this work contributes to theoretical and practical understanding of identity management in the workplace and across cultures. Copyright © 2014 John Wiley & Sons, Ltd.     

Coupling PCSWMM and WASP to Evaluate Green Stormwater Infrastructure Impacts to Storm Sediment Loads in an Urban Watershed

We coupled rainfall–runoff and instream water quality models to evaluate total suspended solids (TSS) in Wissahickon Creek, a mid‐sized urban stream near Philadelphia, Pennsylvania. Using stormwater runoff and instream field data, we calibrated the model at a subdaily scale and focused on storm responses. We demonstrate that treating event mean concentrations as a calibration parameter rather than a fixed input can substantially improve model performance. Urban stormwater TSS concentrations vary widely in time and space and are difficult to represent simply. Suspended and deposited sediment pose independent stressors to stream biota and model results suggest that both currently impair stream health in Wissahickon Creek. Retrofitting existing detention basins to prioritize infiltration reduced instream TSS loads by 20%, suggesting that infiltration mitigates sediment more effectively than detention. Infiltrating stormwater from 30% of the watershed reduced instream TSS loads by 47% and cut the frequency of TSS exceeding 100 mg/L by half. Settled loads and the frequency of high TSS values were reduced by a smaller fraction than suspended loads and duration at high TSS values. A widely distributed network of infiltration‐focused projects is an effective stormwater management strategy to mitigate sediment stress. Coupling rainfall–runoff and water quality models is an important way to integrate watershed‐wide impacts and evaluate how management directly affects urban stream health.     

Toxaphene and other chlorinated compounds in human milk from northern and southern Canada: a comparison.

Human milk from residents of northern Canada (Keewatin) was compared to that in national surveys of southern Canada with respect to residues of toxaphene, PCBs, PCDD/PCDFs, chlordane, and several other persistent organic compounds. Concentrations of toxaphene were approximately ten-fold higher in specimens from Keewatin than from the south. Toxaphene concentrations in samples from the Great Lakes Basin collected in 1992 were not significantly (p < 0.05) different from those of the rest of Canada; however they were significantly (p < 0.05) lower than concentrations reported in a 1986 survey. Hexachlorobenzene, trans nonachlor and oxychlordane were three to five times higher in concentration in the Keewtin samples than in samples reported in the 1992 national survey. Total PCB congeners, DDTs, PCDD/PCDFs, and other chlorinated compounds were not significantly higher in northern samples.     

Etude de l'accumulation du cadmium par une bacterie marine en fonction des conditions de cultures

The influence of different cultural conditions (temperature, salinity, pH, organic matter and cadmium concentration, presence of sulfhydryl groups) on the accumulation of cadmium by a Cd resistent marine bacterium was investigated. The results showed that each of these parameters modify to a certain extent both biomass production and cadmium accumulation. This work emphasizes the need for a higher standardization of toxicity tests to ensure a better reliability of results.